Will freezing temperatures in spring harm trees and shrubs?

Question:

Will trees and shrubs be seriously harmed if they begin to leaf out and are then subjected to freezing temperatures in spring?

Answer:

In some years, warm late winter temperatures can cause some trees and shrubs to break bud, leaf-out, or develop flower buds earlier than normal.  The inevitable below-freezing temperatures that follow in early spring can potentially cause damage to these plants.  In most cases, early leaf and flower development will be just fine with cold temperatures.  If temperatures are cold enough, however, then damage could occur.  There are no practical measures you can take to fully protect trees and shrubs from cold damage, but even if you could, they are not necessary.

The most visible damage will likely occur on spring-flowering trees and shrubs. Freezing temperatures may damage or destroy the flowers on pussy willows, magnolias and other trees and shrubs that bloom in early spring.  While the flowers are lost for that growing season, the trees themselves should not be seriously harmed. Provided the weather conditions are favorable, gardeners can enjoy the bloom on these plants next year.

Freezing temperatures may also damage or destroy newly emerged foliage. Fortunately, trees and shrubs have the ability to leaf out again if the initial growth is damaged or destroyed. Healthy, well-established trees and shrubs should not be greatly harmed and will produce additional growth within a few weeks. Good care during the remainder of the year, such as watering during dry periods, should aid the recovery of trees and shrubs planted within the past 3 to 5 years.